SIGNAL MULTIPLEXER

PURPOSE:To eliminate the need for provision of required amount for HG for the capacity of a ROM generating a control signal multiplexing a signal by using an HG select signal to control an address of the ROM provided separately. CONSTITUTION:A counter load signal synchronizing with a frame signal is inputted to a counter 11 and an output signal of the counter 11 decides the address of the 1st ROM12 and the 2nd ROM15. The output of the 1st ROM12 is independent of the HG select signal and controls the address of a RAM13 and repeats alternately the read/write states in one time slot. On the other hand, the 2nd ROM15 is controlled by the HG select signal and outputs a signal with different data bit. When the output of the 2nd ROM15 is inputted to a selector 14, the input signal inputted via channels 7a-7f is controlled and its output signal changes a time slot writing a data to the RAM13. Thus, the output of the RAM13 is multiplexed onto the HG designated by the HG select signal.